I would like to be able to add a column for parent changeset and the changeset number in a different xlinked repo. Modified file count, or SLOC (as in "Analyze differences") could be useful too. Perhaps add a button to populate the slow columns on demand?

2) Be able to create custom columns, correct? This is slightly more tricky since it can have an impact on the view calculation. I mean, you can create a column but if it takes long to calculate, the entire rendering can be potentially affected.